564. SARS-CoV-2 Ferritin Nanoparticle Vaccines Elicit Broad SARS Coronavirus Immunogenicity

Background The zoonotic emergence of SARS-CoV-2 quickly developed into a global pandemic. Multiple vaccine platforms have been advanced to clinical trials and emergency use authorization. The recent emergence of SARS-CoV-2 virus variants with Spike receptor-binding domain (RBD) and N-terminal domain (NTD) mutations, highlights the need for next-generation vaccines that can elicit immune responses that are resilient against Spike mutations. Methods Using a structure-based vaccine design approach, we developed multiple optimized SARS-CoV-2 nanoparticle immunogens that recapitulate the structural and antigenic profile of the SARS-CoV-2 prefusion spike. We assessed these immunogens in murine immunogenicity studies and in a K18-hACE2 transgenic mouse model with a SARS-CoV-2 challenge. Immune sera from vaccinated mice were assessed for SARS-CoV-2 binding, and neutralization against SARS-CoV-2, variants of concern, and the heterologous SARS-CoV-1 virus. Results In combination with a liposomal-saponin based adjuvant (ALFQ), these immunogens induced robust binding, ACE2-inhibition, and authentic virus and pseudovirus neutralization. A Spike-Ferritin nanoparticle (SpFN) vaccine elicited neutralizing ID50 titers >10,000 after a single immunization, while RBD-Ferritin (RFN) nanoparticle immunogens elicited ID50 titer values >10,000 values after two immunizations. Purified antibody from SpFN- or RFN-immunized mice was transfused into K18-ACE2 transgenic mice and challenged with a high-dose SARS-CoV-2 virus stock. In order to understand the breadth of vaccine-elicited antibody responses, we analyzed SpFN- and RBD-FN-immunized animal sera against a set of heterologous SARS-CoV-2 RBD variants and SARS-CoV RBD. High binding titers with ACE2-blocking activity were observed against SARS-CoV-2 variants and the heterologous SARS-CoV-1 RBD. Furthermore, both SpFN- and RFN-immunized animal sera showed SARS-CoV-1 neutralizing ID50 titers of >2000. Conclusion These observations highlight the importance of SARS-CoV-2 neutralizing antibody levels in providing protection against emerging SARS-like coronaviruses and provide a robust platform for pandemic preparedness. Structure-based design enables development of a SARS-CoV-2 nanoparticle immunogen. Disclosures All Authors: No reported disclosures

Efficacy of “Essential Iodine Drops” against Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2)

Background Aerosolization of respiratory droplets is considered the main route of coronavirus disease 2019 (COVID-19). Therefore, reducing the viral load of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) shed via respiratory droplets is potentially an ideal strategy to prevent the spread of the pandemic. The in vitro virucidal activity of intranasal Povidone-Iodine (PVP-I) has been demonstrated recently to reduce SARS-CoV-2 viral titres. This study evaluated the virucidal activity of the aqueous solution of Iodine-V (a clathrate complex formed by elemental iodine and fulvic acid) as in Essential Iodine Drops (EID) with 200 μg elemental iodine/ml content against SARS-CoV-2 to ascertain whether it is a better alternative to PVP-I. Methods SARS-CoV-2 (USAWA1/2020 strain) virus stock was prepared by infecting Vero 76 cells (ATCC CRL-1587) until cytopathic effect (CPE). The virucidal activity of EID against SARS-CoV-2 was tested in three dilutions (1:1; 2:1 and 3:1) in triplicates by incubating at room temperature (22 ± 2°C) for either 60 or 90 seconds. The surviving viruses from each sample were quantified by a standard end-point dilution assay. Results EID (200 μg iodine/ml) after exposure for 60 and 90 seconds was compared to controls. In both cases, the viral titre was reduced by 99% (LRV 2.0). The 1:1 dilution of EID with virus reduced SARS-CoV-2 virus from 31,623 cell culture infectious dose 50% (CCID50) to 316 CCID50 within 90 seconds. Conclusion Substantial reductions in LRV by Iodine-V in EID confirmed the activity of EID against SARS-CoV-2 in vitro, demonstrating that Iodine-V in EID is effective at inactivating the virus in vitro and therefore suggesting its potential application intranasally to reduce SARS-CoV-2 transmission from known or suspected COVID-19 patients.

The Novel Halovirus Hardycor1, and the Presence of Active (Induced) Proviruses in Four Haloarchaea

The virus Hardycor1 was isolated in 1998 and infects the haloarchaeon Halorubrum coriense. DNA from a frozen stock (HC1) was sequenced and the viral genome found to be 45,142 bp of dsDNA, probably having redundant, circularly permuted termini. The genome showed little similarity (BLASTn) to known viruses. Only twenty-two of the 53 (41%) predicted proteins were significantly similar to sequences in the NCBI nr protein database (E-value ≤ 10−15). Six caudovirus-like proteins were encoded, including large subunit terminase (TerL), major capsid protein (Mcp) and tape measure protein (Tmp). Hardycor1 was predicted to be a siphovirus (VIRFAM). No close relationship to other viruses was found using phylogenetic tree reconstructions based on TerL and Mcp. Unexpectedly, the sequenced virus stock HC1 also revealed two induced proviruses of the host: a siphovirus (Humcor1) and a pleolipovirus (Humcor2). A re-examination of other similarly sequenced, archival virus stocks revealed induced proviruses of Haloferax volcanii, Haloferax gibbonsii and Haloarcula hispanica, three of which were pleolipoviruses. One provirus (Halfvol2) of Hfx. volcanii showed little similarity (BLASTn) to known viruses and probably represents a novel virus group. The attP sequences of many pleolipoproviruses were found to be embedded in a newly detected coding sequence, split in the provirus state, that spans between genes for integrase and a downstream CxxC-motif protein. This gene might play an important role in regulation of the temperate state.

In Vitro Efficacy of “Essential Iodine Drops” Against Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2)

BackgroundAerosolization of respiratory droplets is considered the main route of coronavirus disease 2019 (COVID-19). Therefore, reducing the viral load of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) shed via respiratory droplets is potentially an ideal strategy to prevent the spread of the pandemic. The in vitro virucidal activity of intranasal Povidone-Iodine (PVP-I) has been demonstrated recently to reduce SARS-CoV-2 viral titres. This study evaluated the virucidal activity of the aqueous solution of Iodine-V (a clathrate complex formed by elemental iodine and fulvic acid) as in Essential Iodine Drops (EID) with 200 μg elemental iodine/ml content against SARS-CoV-2 to ascertain whether it is a better alternative to PVP-I.MethodsSARS-CoV-2 (USAWA1/2020 strain) virus stock was prepared by infecting Vero 76 cells (ATCC CRL-1587) until cytopathic effect (CPE). The virucidal activity of EID against SARS-CoV-2 was tested in three dilutions (1:1; 2:1 and 3:1) in triplicates by incubating at room temperature (22 ± 2°C) for either 60 or 90 seconds. The surviving viruses from each sample were quantified by a standard end-point dilution assay.ResultsEID (200 μg iodine/ml) after exposure for 60 and 90 seconds was compared to controls. In both cases, the viral titre was reduced by 99% (LRV 2.0). The 1:1 dilution of EID with virus reduced SARS-CoV-2 virus from 31,623 cell culture infectious dose 50% (CCCID50) to 316 CCID50 within 90 seconds.ConclusionSubstantial reductions in LRV by Iodine-V in EID confirmed the activity of EID against SARS-CoV-2 in vitro, demonstrating that Iodine-V in EID is effective at inactivating the virus in vitro and therefore suggesting its potential application intranasally to reduce SARS-CoV-2 transmission from known or suspected COVID-19 patients.

In-vitro Evaluation of Antiviral Activity of Moringa oleifera Extracts against Polio virus

Background: Moringa oleifera plant parts extract have been utilized tremendously in traditional medicine, having various pharmaceutical activities such as antifungal, antibacterial and antiviral properties. Aim: This study was carried out to evaluate antiviral activity of aqueous extract of Moringa leaves, seeds and flowers against Polio virus isolates (Vaccine Strains P1&P3), MDG-17-04852; MDG-17-04881. Study Design: This is a baseline study carried out to determine the efficacy of Moringa oleifera in the treatment of poliomyelitis. Place and Duration of Study: This study was carried out at the University of Maiduguri Teaching Hospital Maiduguri and Abubakar Tafawa Balewa University, Bauchi from September 2018 to October, 2019. Methods: Phytochemical substances was extracted and screened from the Moringa using standard laboratory techniques. Continuous cell line L20B cells was used to isolate polio virus. Polio virus stock was prepared and titration was carried out to determine TCID50 by Kerber’s formula, L-d(S - 0.5). Cytotoxicity of the extracts was evaluated using the end-point cytopathic effect assay. Antiviral assay and Polio virus Intratypic Differentiation (ITD) was performed using Real-Time PCR. Results: The results revealed present of Tannins in leaves and flowers, Alkaloids and Saponins in all the extracts, Glycosides and Steroids in leaves and Flavonoids in flowers only. Cytotoxicity of the extracts shows 50% effects in 100mg and 50mg concentrations, while 33.3% and 16.7% was observed in 25mg and 12.5mg (P>.05). The titration of the tissue culture infective dose 50% (TCID50) shows that Polio virus type 1and 3 had a titre value of 106.5 and 106.25 respectively. The ITD results observed presence of Sl1 and Sl3 from the extracts. Conclusion: This study found that the Moringa extracts did not neutralized the Polio virus strains studied, as the phytochemicals show no antiviral activity. Therefore further study is needed in this area to ascertain its antiviral potentials against poliomyelitis.

Efficacy of “Essential Iodine Drops” Against Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2)

Background: Aerosolization of respiratory droplets is considered the main route of coronavirus disease 2019 (COVID-19). Therefore, reducing the viral load of Severe Acute Respiratory SyndromeCoronavirus 2 (SARS-CoV-2) shed via respiratory dropletsis potentially an ideal strategy to prevent the spread of the pandemic. The in vitro virucidal activity of intranasal Povidone-Iodine (PVP-I) has been demonstrated recently to reduce SARS-CoV-2 viral titres. This study evaluated the virucidal activity of the aqueous solution of Iodine-V (a clathrate complex formed by elemental iodine and fulvic acid) as in Essential Iodine Drops (EID) with 200 µg elemental iodine/ml content against SARS-CoV-2 to ascertain whether it is a better alternative to PVP-I. Methods: SARS-CoV-2 (USAWA1/2020 strain) virus stock was prepared by infecting Vero 76 cells (ATCC CRL-1587) until cytopathic effect (CPE). The virucidal activity of EID against SARS-CoV-2 was tested in three dilutions (1:1; 2:1 and 3:1) in triplicates by incubating at room temperature (22 ± 2°C) for either 60 or 90 seconds. The surviving viruses from each sample were quantified by a standard end-point dilution assay. Results: EID (200 µg iodine/ml) after exposure for 60 and 90 seconds was compared to controls. In both cases, the viral titre was reduced by 99% (LRV 2.0). The 1:1 dilution of EID with virus reduced SARS-CoV-2 virus from 31,623 cell culture infectious dose 50% (CCCID50) to 316 CCID50 within 90 seconds. Conclusion: Substantial reductions in LRV by Iodine-V in EID confirmed the activity of EID against SARSCoV-2 in vitro, demonstrating that Iodine-V in EID is effective at inactivating the virus in vitro and therefore suggesting its potential application intranasally to reduce SARS-CoV-2 transmission from known or suspected COVID-19 patients.

Molecular Characterization of Echovirus 30 Isolated from Environment in North India

BackgroundEchovirus 30 (E30) causes acute aseptic meningitis. Enteroviruses (EVs) are responsible for 30,000 to 50,000 hospitalizations for aseptic meningitis per year in the United States. E30 is one of the most frequently isolated EVs, causing extensive outbreaks in temperate climates in several countries. MethodsE30 used in this study was isolated from environmental specimens. The virus was confirmed by RT-PCR with specific primers (1). Virus stock was prepared by infecting RD cells in 25 cm2 flasks (Corning Inc. USA). Virus infected and mock infected cells were incubated at 36.5 ºC with 2% MEM. After 48 h of infection, the culture was aliquoted and kept at-80 ºC for further use.ResultsThis present work analyzed the E30 genetic diversity in a fragment of 217 nucleotides of the VP1 region, of environmental strains. The environmental samples of echovirus 30 show mutation in the nonfunctional polyprotein protein (Fig. 1). The result suggested that the information may be obtained by analyzing only a part of the VP1 region.ConclusionThe present study showed that the E30 environmental sample is more divergent to prototype Bastianni strain.

Quantification of SARS-CoV-2 neutralizing antibody by a pseudotyped virus based assay

Jianhui Nie, Qianqian Li, and Jiajing Wu contributed equally to this work.Pseudotyped viruses are useful virological tools due to their safety and versatility. Based on a VSV pseudotyped virus production system, we developed a pseudotyped virus-based neutralization assay against SARS-CoV-2 in biosafety level 2 facilities. This protocol includes production, titration of the SARS-CoV-2 S pseudotyped virus and neutralization assay based on it. Various types of samples targeting virus attachment and entry could be evaluated for their potency, including serum samples derived from animals and humans, monoclonal antibodies, fusion inhibitors (peptides or small molecules). If the pseudotyped virus stock has been prepared in advance, it will take 2 days to get the potency data for the candidate samples. Experience of handling cells is needed before implementing this protocol.

Identification of Dezidougou Virus in a DAK AR 41524 Zika Virus Stock

ABSTRACT We report here the complete genome of a Dezidougou virus (DEZV) isolated from a passaged culture of the Zika virus strain DAK AR 41524. The consensus DEZV sequence we recovered shows 99% nucleotide similarity using BLASTN to a previously reported DEZV (accession no. JQ675604.1). The current sequence has additional repeat regions as well as a deleted repeat region, which we confirmed by Sanger sequencing, that were not present in the originally published sequence, JQ675604.1.

Effect of lyophilization on infectivity and viral load of Adenovirus

Freeze drying (Lyophilization) performed at temperature and pressure below the triple point is being practiced for the preservation of virus stocks for longer periods. The present study is aimed to lyophilize adenovirus strain to study its effects on infectivity and viral load. In-house adenovirus reference strain (stock virus) was propagated in Hep-2 cell line in 25cm2 cell culture flasks. In 24-well plates the serial dilutions of stock virus from 10-1 to 10-7 (100μl inoculum) was inoculated in each well with Hep-2 cells for TCID50 titer and viral DNA was extracted separately to determine viral load by Taqman Real Time PCR. Stock virus was lyophilized in 3 lots and stored at RT (25±2°C) and 4°C separately for 1, 4 and 6 months and subjected to TCID50 (for viral infectivity) and viral load assay (for total viral genome copies). Following lyophilisation and storage of adenoviral strains at RT and 4°C separately did not affect significantly on the viral stability, infectivity as well as viral copy number till 4 months. However, storage at RT for 6 months resulted in 1 log reduction in viral copy number. Thus, storage of even lyophilized virus stock would necessitate a temperature of at least 4°C for prolonged periods. The present study could successfully lyophilize adenovirus and retain its infectivity over a period of 6 months when stored at RT and 4°C. No significant difference in the infectivity or TCID50 titer was observed in the lyophilized virus as compared to the stock virus. However, the viral load was observed to increase with lyophilization of the virus over 6 months when stored at 4°C which possibly is due to the concentration of the virus on freeze-drying.Nepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 15-21